The Breast Tissue Core will be supported by the Human Tissue Resource Core (HTRC) of the University of Chicago, Department of Pathology, which is dedicated to the collection, storage and distribution of breast tumors for research. Because our institution sees large numbers of new breast oncology patients each year, our access to patient derived tissues for research is high. The UC has greater than 10 years of experience with prospective and retrospective UC breast cancer tissue collection (bank containing more than 5000 archived diagnostic cases and more than 150 fresh frozen samples to date). The UC HTRC facility also has significant expertise in tumor banking and specimen handling for downstream research studies. The Breast Tissue Core (BTC) will facilitate both the collection of fixed embedded and fresh frozen tissues as well as acquisition and database storage of essential pathologic and clinical information needed for conducting translational research. The major aim of this proposal is the establishment a state of art Breast Tissue Core for human and animal specimens, which will benefit not only the CPHHD investigators, but will facilitate research activities of other scientists within and outside the parent institution. With time and accrual we will be willing to participate in NCI-supported tissue networks to extend the benefits of this resource beyond our institution. This process will be supervised by a Tissue Review and Disbursement Committee (including physicians, biologists and pathologists), and reviews by the individual institutional Review Boards (IRBs) on an annual basis. Aims: 1) Develop a unique comprehensive resource for investigators involved in diagnosis and treatment of breast cancer patients, 2) Assist in discovery/development of new histologically relevant oncology therapeutics, 3) Apply advance technology and deliver patient specific diagnostic and prognostic information in a clinical selffing, 4) Effectively integrate and utilize tissue resources and information from animal models that will positively impact on the survival of breast cancer patients.